Pretty much anyone defending the postal worker here on the basis of what she did being "right" is missing the generalisation that must be made. If it's okay for postal workers to refuse to deliver mail containing viewpoints they disagree with, that means it's okay for bigoted postal workers to refuse to deliver mail from or to LGBT organisations. It means it would be okay for pro-life postal workers to refuse to deliver parcels containing birth control pills or flyers containing information about abortion services.
You cannot have it both ways. If you make a rule that there are cases when it is acceptable for postal workers to destroy or refuse to deliver mail, it will be used by the other side against you.
Law enforcement shouldn't be able to get into someone's mobile phone without a warrant anyway. All this change does is frustrate attempts by police to evade going through the proper legal procedures and abridging the rights of the accused.